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Making libGDX's data structures implement JDK interfaces.

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/*
 * Copyright (c) 2025 See AUTHORS file.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.github.tommyettinger.ds.support.util;

import com.github.tommyettinger.function.BooleanPredicate;

import java.util.NoSuchElementException;

/**
 * Wraps an Iterator so that it calls a function on each item it would otherwise return, and returns that function's
 * result. The function in this is actually a predicate, since all function types in Funderby that return booleans are
 * considered predicates.
 * If you need to return a different type than what the iterator returns, you can use an {@link AlteringIterator}.
 * This has undefined behavior if any items the Iterator could return are modified during iteration.
 * 

 * You can change both the Iterator and editor at once using {@link #set(BooleanIterator, BooleanPredicate)} ,
 * and can also just change the Iterator with {@link #set(BooleanIterator)}.
 */
public class EditingBooleanIterator implements BooleanIterator {
    public BooleanIterator iterator;
    public BooleanPredicate editor;

    public EditingBooleanIterator() {
    }

    public EditingBooleanIterator(final BooleanIterator iterator, final BooleanPredicate editor) {
        set(iterator, editor);
    }

    public void set (final BooleanIterator iterator, final BooleanPredicate editor) {
        this.iterator = iterator;
        this.editor = editor;
    }

    public void set (final BooleanIterator iterator) {
        set(iterator, editor);
    }

    @Override
    public boolean hasNext () {
        return iterator.hasNext();
    }

    @Override
    public boolean nextBoolean () {
        if (!hasNext()) throw new NoSuchElementException("No elements remaining.");
        return editor.test(iterator.nextBoolean());
    }

    @Override
    public void remove () {
        iterator.remove();
    }
}